Conventionally, in a semiconductor device such as a semiconductor light emitting device that uses a semiconductor light emitting element as a light source, or a power semiconductor device having a semiconductor element for power control, etc., a sealing resin is used to protect semiconductor elements and wiring from outside air that contains dust, moisture, etc. In a semiconductor light emitting device, among sealing resins, there are resins that contain phosphor for light conversion.
However, with a semiconductor light emitting device or a semiconductor device, the thermal stress is high due to use at high temperature and high current, and since peeling of the sealing resin from the metal plating on the lead frame or ceramic substrate occurs easily, though other characteristics are good, these cannot be used as products in some cases. Methods are known of using an anchor effect as a countermeasure for this peeling of the sealing resin from the metal.
As methods that use the anchor effect, in the contact interface of the sealing resin and the substrate surface, there is a method of making a substrate surface be a rough surface with recesses and projections (see International Patent Publication No. WO2017/022755, for example), or a method of providing holes (see Japanese Unexamined Patent Publication No. 2011-228369, for example). In addition, there are methods of curving a copper frame end surface that contacts the side surface of the sealing resin (see Japanese Unexamined Patent Publication No. 2011-035082, for example), or that forms recesses and projections on the side surface of a cavity made from molding resin (see International Patent Publication No. WO2011/052672, for example). Furthermore, there are methods in which an anchor effect can be expected in manufacturing of a composite substrate in which an electrode is formed by baking an electrically conductive paste that contains resin at a temperature that will burn away the resin component, and a ceramic substrate and a resin substrate are bonded (see Patent International Patent Publication No. WO2006/043474, for example).